Method for pressure casting

US3964537A · kind A · utility

Assignee

• Gebrueder Buehler AG · CH

Inventors

• Peter Koch · Wulfen, DE
• Eduard Beyer · Gossau, CH

Key dates

• Filing date: Oct 3, 1974
• Grant date: Jun 22, 1976
• Expiry date: Oct 3, 1994

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B22D17/32
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

In the method, a shot sleeve, for receiving a metered quantity of melt through an inlet or filling opening and connected to the mold cavity, has its volume continuously diminished in such a manner as to maintain a constant communication between the space above the melt in the shot sleeve and the mold cavity for escape of all the gas or air above the melt into the mold cavity before the opening of the shot sleeve into the mold cavity is completely closed by the advancing melt. This is effected, during the shot-pre-filling phase, by an accelerated motion of an injection piston from a rest position, at which the filling inlet to the shot sleeve is open, through the shot sleeve toward the mold cavity opening. As a result of the accelerated motion of the piston, the melt spreads over the melt engaging surface of the injection piston and the formation of a standing wave is prevented. During the mold-filling phase immediately following the pre-filling phase, as soon as the melt surface has reached the casting gate leading to the mold, the metered quantity of melt is displaced through the casting gate into the mold cavity. The mold-fillling phase, which follows the pre-filling phase, may b…